Synthesis and properties of Sr-free Bi cuprate superconductors

Both the oxygen content and T^onset _c of the Bi₂Ca_2.5(Ln, Ln⁺)_0.5Cu₂O _y system monotonically increases as the mean ionic radius of (Ln, Ln⁺) increases. The structural modulations in all of the samples are almost commensurate with a period equal to 9b. In Bi_2-xPbCa_2.5Nd_0.5Cu₂O _y , T^onset _c decreases with increasing Pb concentration. In order to investigate the effect of post annealing using a hot isostatic press (HIP), Bi₂Ca_2.5La_0.25Pr_0.25Cu₂O _y was processed under different HIP conditions. This result suggested that HIP annealing causes a phase change from the 232 structure to the 221 structure.     

Spatial light manipulation devices using nonlinear polymeric materials

An electrically addressed spatial light modulator with 5 × 5 pixels is designed using nonlinear polymeric materials. Resonator structure for the material is proposed to minimize the driving voltages. Side-chain polymer poly-orange tom-1 isophoronedisocyanate (r ₃₃ = 23 pm/V) is used as a material. A modulation efficiency of 4.7% has been realized with 5.1 V_rms applied voltage at a wavelength of 633 nm. Very fast modulation at over 10 MHz has been demonstrated.     

A novel trinuclear palladium cluster compound: di‐μ3‐chloro‐tris­[chloro(tri­phenyl­phosphine‐P)­palladium] acetone solvate

The title triangular tripalladium cluster, [Pd₃­Cl₅­(C₁₈­H₁₅P)₃]·­C₃H₆O, (I), has a trigonal‐bipyramidal framework of Pd₃(μ₃‐Cl)₂, with the two Cl atoms in apical positions. Each Pd atom in the framework has two additional coordination sites to establish square‐planar cis‐PdL₂(μ₃‐Cl)₂ geometry. Three P atoms are located on the same side of the plane defined by the Pd₃ triangle, which leads to a pseudo‐C_3v symmetry for the core framework of Pd₃(μ₃‐Cl)₂P₃Cl₃. The average Pd—Cl distance trans to PPh₃ is 2.473 (8) Å, which is significantly longer than the average Pd—Cl distance of 2.294 (4) Å for those trans to terminal Cl, due to the strong trans effect of a P atom compared with a Cl atom. Compound (I) has 49 valence electrons and shows a rhombic electron‐spin resonance signal, indicating an S = ½ ground state.     

Preconcentration of some phosphorus-containing anions by adsorption on hydrated iron(III) oxide

The adsorption behaviour of orthophosphate, triphosphate, pyrophosphate, monomethylphosphate, phosphite, α- and β-glycerophosphates, dimethylphosphate, and hypophosphite on hydrated iron(III) oxide precipitate is studied as a function of pH. Orthophosphate is adsorbed quantitatively at pH 4.0–8.0, triphosphate and pyrophosphate at pH 4–9.3 and the next three compounds at pH 4–6.8. The last two ions were only slightly adsorbed at any pH examined.     

Evaluation of effects of novel urease inhibitor, N-(pivaloyl)glycinohydroxamic acid on the formation of an infection bladder stone using a newly designed urolithiasis model in rats

By using our new infection stone model of a rat, we evaluated the effect of a novel urease inhibitor, N-(pivaloyl)glycinohydroxamic acid (P-GHA), on the formation of an infection bladder stone. The oral dosing of P-GHA significantly inhibited the elevation of the urinary ammonia level of rats having the urinary tract infection with Proteus mirabilis. A short term regimen (7 d, 730 +/- 38 mg/kg) with P-GHA significantly inhibited the development of the infection bladder stone. Furthermore, a long term combination regimen (11 d) of P-GHA and aminobenzylpenicillin markedly inhibited the development of the infection bladder stone, and also caused a very slight renal impairment to the rats tested in contrast with the method of Vermeulen et al. Our infection stone model in rats, therefore, seems to be useful for the evaluation of therapeutic agents in long term examinations.     

Cluster—cracking Reaction,a New Method to Synthesize Unsymmetrical Dithiolate Complexes for the Study of Third—Order Nonlinear Optical Properties

A new coluster-cracking method to synthesize dithiolate metal complexes was reported and four unsymmetric complexes with formula(Me4N)2[M(Ln)(SPh)2](M=Cd and Zn,L1=dmit=1,3-dithiole-2-thione4-5,dithiolate,L2=dmid=1,3-dithiole-2-one-4,5-dithiolate,SPh=thiophenolate)(1-4)were characterized by elemental analysis,IR,UV NMR spectra and so on.The advantages of this method are summarized in two aspects:(1) the preparation is very convenient;(2) the reaction usually completed giving the product with high pruity.The crystal structure of 1 showed that the bond distances of Cd(Ⅱ）to the sulfur of the thiophenolate group are shorter than those of Cd(Ⅱ）to the sulfur of dmit,so that the thiophenolate group does not be replaced in the reaction and thmixed ligand complexes are the dominant produxts.The dmit complexes showed well third-order NLO properties,but not of the dmid complexes,although dmid is an analogue to dmit.     

Effects of a novel urease inhibitor, N-(diaminophosphinyl)isopentenoylamide on the infection stone in rats

We evaluated the effect of a novel potent urease inhibitor, N-(diaminophosphinyl)isopentenoylamide (IPA), on the development of an infection bladder stone using our urolithiasis model in rats. IPA was excreted into urine after oral administration to rats, and the cumulative urinary recovery rate of unchanged IPA reached about 29.6% within 24 h (50 mg/kg). The oral administration of IPA (6.25 mg/kg, b.i.d., 5 d) significantly inhibited the development of the infection bladder stone. The present result suggests that IPA is a very promising compound in the prevention of formation and recurrence of an infection stone owing to a high efficacy and a low toxicity of IPA in animals.     

Comparisons of spore dosimetry and spectral photometry of solar-UV radiation at four sites in Japan and Europe

In order to develop monitoring and assessment systems of biologically effective doses of solar-UV radiation, concurrent measurements of spectral photometry and spore dosimetry were conducted in summer months at four sites in Japan and Europe. Effectiveness spectra were derived by multiplying spectral irradiance in 0.5 nm steps between 290 and 400 nm with the inactivation efficiency of the spores determined using monochromatic radiation of fine wavelength resolution. Shapes of the effectiveness spectra were very similar at the four sites exhibiting major peaks at 303.5, 305.0, 307.5 and 311.0 nm. The dose rates for spore inactivation from direct survival measurements and from calculations by the integration of the effectiveness spectra were compared for 174 data points. The ratios (observed/calculated) of the two values were concordant with a mean of 1.26 (+/- 0.24 standard deviation [SD]). The possible causes for the variations and slightly larger observed values are discussed.     

Bridged silver(I) complexes of the polycyclic aromatic compounds tetraphenylethylene and 1,1,4,4-tetraphenyl-1,3-butadiene

For the purpose of investigating the coordination behavior of the sterically congested alkenes and exploring the possibility of cofacial complexation in the polycyclic aromatic system for formation of extended polymeric networks, tetraphenylethylene (tphe) and 1,1,4,4-tetraphenyl-1,3-butadiene (tphb) have been studied with regard to their complexation with a silver(I) ion. The crystal structures of [Ag(tphe)(ClO4)(p-xylene)], [Ag2(tphe)(ClO4)2], [Ag4(tphe)(CF3SO3)4], [Ag2(tphb)(ClO4)2], and [Ag2(tphb)(CF3SO3)2], together with the metal-free ligands tphe and tphb, have been determined by single-crystal X-ray diffraction. The pi-electron-rich cleft in organic components is found to offer a potential site for complexation, which can be utilized to generate an interesting array of organometallic compounds with one- and two-dimensional frameworks.